Hey everybody , I've been fooling with amps for a little while , but I'm no expert tech . I'm sure that I read in some places that because of the higher than typical voltage on the cathode of a tube being used as a "cathode follower" , that the tube in that position can be more prone to filliment hum . I had a situation where my friend's amp(Bluesbreaker) started to develope a hum and I changed out that tube (V2) and the hum went away . Someone suggested that the reason that the hum went away, must have been because the replacment tube was probably a "weaker" tube and that it was not picking up the hum that's in the amp ...But , I don't think that the amp sounds "weak" . His feeling is that TUBES don't hum , AMPS HUM . I could swear that I've even had some brand new tubes hum more than others , right out of the box ...and that the quiet tubes didn't seem weaker than the humming tubes ....Am I right , or wrong ? Thanks for any replies , Chris .